{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,20]],"date-time":"2026-08-20T05:23:49Z","timestamp":1787203429886,"version":"build-2736575974"},"reference-count":46,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T00:00:00Z","timestamp":1787011200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000002","name":"National Institutes of Health","doi-asserted-by":"crossref","award":["P2CHD101899"],"award-info":[{"award-number":["P2CHD101899"]}],"id":[{"id":"10.13039\/100000002","id-type":"DOI","asserted-by":"crossref"}]},{"award":["P2CHD101899"],"award-info":[{"award-number":["P2CHD101899"]}],"id":[{"id":"https:\/\/ror.org\/01cwqze88","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Smartphone accelerometry could enable longitudinal home-based balance testing, yet its reliability across tasks and outcome measures must be established. We assessed the test\u2013retest reliability and measurement precision of a custom smartphone balance application. Sixty-nine healthy, community-dwelling middle-aged and older adults (ages 41\u201376 years) performed a 5 s home-based balance assessment weekly for 3 weeks. The assessment was directed by the application, which generated accelerometer-based sway metrics. Participants performed two 30 s trials each of feet together and tandem stance (eyes open, eyes closed) and single leg stance (eyes open only). Intraclass correlation coefficients (ICCs) and relative standard error of measurement (SEM%) were calculated for time-domain and frequency-domain measures. Outcomes achieved good-to-excellent reliability when averaged across three weekly assessments (ICC = 0.59\u20130.95), particularly mediolaterally. Time-domain measures, particularly mean acceleration (ICC = 0.84\u20130.92; SEM% = 11.1\u201323.5%), were the most reliable and precise outcomes overall, while frequency-domain measures showed lower reliability and precision at higher spectral bands (ICC as low as 0.59; SEM% up to 41.5%). As standing tasks became more difficult, reliability and precision declined correspondingly. We conclude that minimally supervised, home-based balance assessment can produce reliable, precise sway measures in healthy, screened, iPhone-owning middle-aged and older adults. This application carries potential for large-scale, remote balance monitoring for research purposes, though validation in more diverse and higher-risk populations will be needed before clinical application can be recommended.<\/jats:p>","DOI":"10.3390\/s26165219","type":"journal-article","created":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T10:22:52Z","timestamp":1787048572000},"page":"5219","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Reliability of a Home-Based Smartphone Balance Assessment in Healthy Middle-Aged and Older Adults"],"prefix":"10.3390","volume":"26","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8210-2163","authenticated-orcid":false,"given":"Elizabeth","family":"Coker","sequence":"first","affiliation":[{"name":"Department of Dance, Tisch School of the Arts, New York University, New York, NY 10003, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5869-025X","authenticated-orcid":false,"given":"Anat V.","family":"Lubetzky","sequence":"additional","affiliation":[{"name":"Department of Physical Therapy, Steinhardt School of Culture, Education, and Human Development, New York University, New York, NY 10010, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,18]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"993","DOI":"10.15585\/mmwr.mm6537a2","article-title":"Falls and Fall Injuries Among Adults Aged \u226565 Years\u2014United States, 2014","volume":"65","author":"Bergen","year":"2016","journal-title":"Morb. 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